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Heart rate variability pattern in adolescent obesity
196A
POSTERS: Obesity, Insulin Resistance, Diabetes
P-455 HEART RATE VARIABILITY PATTERN IN ADOLESCENT OBESITY Andrea Conterno, Bernard Silke, Franco Rabbia, Tiziana Grosso, Ivana Rabbone, Barbara De Vito, Fulvio Morello, Cristina Paglieri, Franco Veglio. Department of Medicine and Experimental Oncology, Hypertension Unit, University of Turin, Turin, Italy; Department of Pharmacology and Therapeutics, Trinity College & St. James Hospital, Dublin, Ireland; Pediatric Department, University of Turin, Turin, Italy. Aim: To investigate the cardiovascular autonomic function during the time course of pediatric obesity using standard spectral heart rate variability (HRV) analysis and non linear methods (scatterplot and quadrant analysis). Methods: 50 obese children (OB) (13.9⫾1.7 ys ) were compared with 13 healthy lean subjects (12.9⫾1.6 ys). OB were classified as recent OB (ROB) (⬍4 ys), intermediate OB (IOB) (⬎4 and ⬍7 ys) and long term OB (⬎ 7 ys). In all participants we performed blood pressure (BP) measures, laboratory tests and 24-h ECG/ambulatory BP monitoring. The spectral power was quantified in total power (TP), low frequency power (LF), index of sympathetic tone, high frequency power (HF), index of vagal tone and LF/HF ratio. Total, long term and short term time domain HRV were calculated. Poincare’ plot and quadrant methods were used to determine HRV with non-linear techniques. Scatterplot length is correlated with long term time domain, while scatterplot width appears a specific measure of parasympathetic nervous system activity. Quadrant analysis removes the dominant characteristics apparent in the Poincare’ plot, namely the high correlation between one interval and the next. Four patterns can be identified: cardiac deceleration (parasympathetic prevalence), balanced sequences, cardiac acceleration (sympathetic prevalence). Results: All OB groups had higher casual and ambulatory BP values and higher fasting glucose, insulin and triglicerides levels. All parameters reflecting parasympathetic tone (HF band, RMSSD, PNN50, scatterplot width) were significantly and persistently reduced in all OB groups in comparison to lean controls. Meantime LF and LF/HF and cardiac acceleration (i.e. consecutive ⌬RR and ⌬RRn⫹1 shorten), reflecting sympathetic activation, were significantly increased in ROB group, whereas LF, but not non linear measures, were similar to lean controls in IOB and OB groups, suggesting a biphasic behaviour of sympathetic tone, whereas non linear analysis showed a decreasing trend toward the duration on obesity. Long term HRV measures were not significantly different in the 4 groups considered. Conclusions: Autonomic nervous system changes in adolescence obesity seems to be related to its time course. Non linear methods of scatterplot and quadrant analysis permits autonomic balance to be assessed, although measuring different aspects of HRV. Key Words: Heart Rate Variability, Non Linear HRV Analysis, Adolescent Obesity
P-456 DETERMINANTS OF NIGHTTIME BP FALL AND DETERIORATION OF CARDIOVASCULAR TARGET ORGANS IN BLACK AND WHITE TYPE 2 DIABETIC PATIENTS Paula Caupers, Domingos Diogo, Albertino Damasceno, Jose A. Silva, Joao Maldonado, Jose L. Medina, Jorge J. Polonia. Faculdade Medicina, Eduardo Mondlane, Maputo, Mozambique; Unidade HT risco CV, Hospital Pedro Hispano, Matosinhos, Portugal; Endocrinologia & Farmacol Clinica, Faculdade Medicina Porto, Porto, Portugal. Cardiovascular morbidity and mortality has been suggested to be greater in black type 2 diabetic patients as compared with caucasians. In both populations, blunting of nighttime BP fall, autonomic neuropathy, albu-
AJH–April 2002–VOL. 15, NO. 4, PART 2
minuria, pulse wave velocity, etc, has been correlated with cardiovascular prognosis. In a cross over study, we evaluated 24-ambulatory BP (ABP), autonomic neuropathy cardiovascular Ewing tests, left ventricular mass index (LVMI), carotid-femoral pulse wave velocity (PWV, Complior) and albuminuria in 83 type 2 diabetic patients either black or caucasian, all treated with oral antidiabetics and with antihypertensive drugs if needed. Only subjects with age 40-65 yrs, diabetes duration ⬍ 10 yrs, daytime BP ⬍ 150/100 mm Hg and normal renal function were included. Black diabetic patients (Black-diab, n⫽39) versus caucasian diabetics (Caucas-diab, n⫽44)did not differ for age 53 (2) v 52 (2) yrs, diabetes duration 4.9 (0.4) v 5.1 (0.5) yrs, daytime BP 132/84 (2/1) v 133/83 (2/1), LVMI 66 (2) v 65 (3) g/m2, glicosilated hemoglobin 8.9 (0.4) v 8.7 (0.3), treatment with antihypertensive drugs 65 v 68 %, percentage of women/total 46 v 48%, and percentage of patients with microalbuminuria 29 v 25 %. However, Black-diab v Caucas-diab showed higher levels of autonomic neuropathy- parasympathetic score 2.9 (0.2) v 1.1 (0.1), total score 3.8 (0.3) v 1.9 (0.2, both p⬍0.01, lower nighttime percenctual fall of systolic blood pressure 4.7 (1.2) v 7.9 (2.0)%, p⬍0.01 and higher PWV values 13.2 (0.6) v 12.1 (0.3)m/s, p⬍0.05. In the overall population, autonomic total score was the variable more strongly correlated with blunting of nighttime BP fall (r⫽-0.523, p⬍0.01). In type 2 diabetics (black and caucasian) autonomic neuropathy may dictate the attenuation of nighttime fall of BP. For similar daytime BP values, Black-diab v Caucas-diab exhibits greater aortic stiffness (PWV) and attenuation of nighttime BP fall along with worse autonomic neuropathy levels that may contribute to Black-diab worse cardiovascular prognosis. Key Words: Autonomic Neuropathy, Diabetes Type 2, Black and Caucasians
P-457 DIFFERENTIAL EFFECTS OF PERINDOPRIL ON HSCRP, FERRITIN, INSULIN AND BLOOD PRESSURE IN HYPERTENSIVE PATIENTS WITH AND WITHOUT THE DYSMETABOLIC SYNDROME X Demetrios A. Perdikis, Giacomo Mangiaracina. Family Medicine, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, NJ, United States; Internal Medicine, Seton Hall University School of Medicine, West Orange, NJ, United States. The dysmetabolic syndrome X represents a constellation of interrelated metabolic derangements among which are insulin resistance, inflammation and hypertension. Tissue-specific angiotensin converting enzyme (ACE) inhibitors exhibit putative anti-inflammatory properties and may ameliorate insulin resistance. We hypothesized that the tissue-specific ACE inhibitor perindopril might influence the course of syndrome X in hypertensive patients. We therefore sought to study its effects in a cohort of eighty-four caucasian hypertensives ranging in age from 35 to 64 years. We quantitated inflammation by hsCRP and ferritin. Insulin resistance was assessed by anthropometric, fasting serum lipid and insulin values. Brachial artery pressure was measured in duplicate in both upper extremities. We identified forty newly diagnosed hypertensives with syndrome X using recently published criteria. All patients received 4 mg of perindopril and were followed for 12 weeks. Perindopril improved all studied biochemical parameters except homocysteine in the non-syndrome X group. There was a statistically significant decrease in cardiac risk in both groups taking perindopril. However, the syndrome X hypertensives exhibited substantial improvement in markers of insulin resistance and inflammation. The biochemically observable metabolic defects in syndrome X are amenable to perindopril therapy in this study.
POSTERS: Obesity, Insulin Resistance, Diabetes
P-455 HEART RATE VARIABILITY PATTERN IN ADOLESCENT OBESITY Andrea Conterno, Bernard Silke, Franco Rabbia, Tiziana Grosso, Ivana Rabbone, Barbara De Vito, Fulvio Morello, Cristina Paglieri, Franco Veglio. Department of Medicine and Experimental Oncology, Hypertension Unit, University of Turin, Turin, Italy; Department of Pharmacology and Therapeutics, Trinity College & St. James Hospital, Dublin, Ireland; Pediatric Department, University of Turin, Turin, Italy. Aim: To investigate the cardiovascular autonomic function during the time course of pediatric obesity using standard spectral heart rate variability (HRV) analysis and non linear methods (scatterplot and quadrant analysis). Methods: 50 obese children (OB) (13.9⫾1.7 ys ) were compared with 13 healthy lean subjects (12.9⫾1.6 ys). OB were classified as recent OB (ROB) (⬍4 ys), intermediate OB (IOB) (⬎4 and ⬍7 ys) and long term OB (⬎ 7 ys). In all participants we performed blood pressure (BP) measures, laboratory tests and 24-h ECG/ambulatory BP monitoring. The spectral power was quantified in total power (TP), low frequency power (LF), index of sympathetic tone, high frequency power (HF), index of vagal tone and LF/HF ratio. Total, long term and short term time domain HRV were calculated. Poincare’ plot and quadrant methods were used to determine HRV with non-linear techniques. Scatterplot length is correlated with long term time domain, while scatterplot width appears a specific measure of parasympathetic nervous system activity. Quadrant analysis removes the dominant characteristics apparent in the Poincare’ plot, namely the high correlation between one interval and the next. Four patterns can be identified: cardiac deceleration (parasympathetic prevalence), balanced sequences, cardiac acceleration (sympathetic prevalence). Results: All OB groups had higher casual and ambulatory BP values and higher fasting glucose, insulin and triglicerides levels. All parameters reflecting parasympathetic tone (HF band, RMSSD, PNN50, scatterplot width) were significantly and persistently reduced in all OB groups in comparison to lean controls. Meantime LF and LF/HF and cardiac acceleration (i.e. consecutive ⌬RR and ⌬RRn⫹1 shorten), reflecting sympathetic activation, were significantly increased in ROB group, whereas LF, but not non linear measures, were similar to lean controls in IOB and OB groups, suggesting a biphasic behaviour of sympathetic tone, whereas non linear analysis showed a decreasing trend toward the duration on obesity. Long term HRV measures were not significantly different in the 4 groups considered. Conclusions: Autonomic nervous system changes in adolescence obesity seems to be related to its time course. Non linear methods of scatterplot and quadrant analysis permits autonomic balance to be assessed, although measuring different aspects of HRV. Key Words: Heart Rate Variability, Non Linear HRV Analysis, Adolescent Obesity
P-456 DETERMINANTS OF NIGHTTIME BP FALL AND DETERIORATION OF CARDIOVASCULAR TARGET ORGANS IN BLACK AND WHITE TYPE 2 DIABETIC PATIENTS Paula Caupers, Domingos Diogo, Albertino Damasceno, Jose A. Silva, Joao Maldonado, Jose L. Medina, Jorge J. Polonia. Faculdade Medicina, Eduardo Mondlane, Maputo, Mozambique; Unidade HT risco CV, Hospital Pedro Hispano, Matosinhos, Portugal; Endocrinologia & Farmacol Clinica, Faculdade Medicina Porto, Porto, Portugal. Cardiovascular morbidity and mortality has been suggested to be greater in black type 2 diabetic patients as compared with caucasians. In both populations, blunting of nighttime BP fall, autonomic neuropathy, albu-
AJH–April 2002–VOL. 15, NO. 4, PART 2
minuria, pulse wave velocity, etc, has been correlated with cardiovascular prognosis. In a cross over study, we evaluated 24-ambulatory BP (ABP), autonomic neuropathy cardiovascular Ewing tests, left ventricular mass index (LVMI), carotid-femoral pulse wave velocity (PWV, Complior) and albuminuria in 83 type 2 diabetic patients either black or caucasian, all treated with oral antidiabetics and with antihypertensive drugs if needed. Only subjects with age 40-65 yrs, diabetes duration ⬍ 10 yrs, daytime BP ⬍ 150/100 mm Hg and normal renal function were included. Black diabetic patients (Black-diab, n⫽39) versus caucasian diabetics (Caucas-diab, n⫽44)did not differ for age 53 (2) v 52 (2) yrs, diabetes duration 4.9 (0.4) v 5.1 (0.5) yrs, daytime BP 132/84 (2/1) v 133/83 (2/1), LVMI 66 (2) v 65 (3) g/m2, glicosilated hemoglobin 8.9 (0.4) v 8.7 (0.3), treatment with antihypertensive drugs 65 v 68 %, percentage of women/total 46 v 48%, and percentage of patients with microalbuminuria 29 v 25 %. However, Black-diab v Caucas-diab showed higher levels of autonomic neuropathy- parasympathetic score 2.9 (0.2) v 1.1 (0.1), total score 3.8 (0.3) v 1.9 (0.2, both p⬍0.01, lower nighttime percenctual fall of systolic blood pressure 4.7 (1.2) v 7.9 (2.0)%, p⬍0.01 and higher PWV values 13.2 (0.6) v 12.1 (0.3)m/s, p⬍0.05. In the overall population, autonomic total score was the variable more strongly correlated with blunting of nighttime BP fall (r⫽-0.523, p⬍0.01). In type 2 diabetics (black and caucasian) autonomic neuropathy may dictate the attenuation of nighttime fall of BP. For similar daytime BP values, Black-diab v Caucas-diab exhibits greater aortic stiffness (PWV) and attenuation of nighttime BP fall along with worse autonomic neuropathy levels that may contribute to Black-diab worse cardiovascular prognosis. Key Words: Autonomic Neuropathy, Diabetes Type 2, Black and Caucasians
P-457 DIFFERENTIAL EFFECTS OF PERINDOPRIL ON HSCRP, FERRITIN, INSULIN AND BLOOD PRESSURE IN HYPERTENSIVE PATIENTS WITH AND WITHOUT THE DYSMETABOLIC SYNDROME X Demetrios A. Perdikis, Giacomo Mangiaracina. Family Medicine, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, NJ, United States; Internal Medicine, Seton Hall University School of Medicine, West Orange, NJ, United States. The dysmetabolic syndrome X represents a constellation of interrelated metabolic derangements among which are insulin resistance, inflammation and hypertension. Tissue-specific angiotensin converting enzyme (ACE) inhibitors exhibit putative anti-inflammatory properties and may ameliorate insulin resistance. We hypothesized that the tissue-specific ACE inhibitor perindopril might influence the course of syndrome X in hypertensive patients. We therefore sought to study its effects in a cohort of eighty-four caucasian hypertensives ranging in age from 35 to 64 years. We quantitated inflammation by hsCRP and ferritin. Insulin resistance was assessed by anthropometric, fasting serum lipid and insulin values. Brachial artery pressure was measured in duplicate in both upper extremities. We identified forty newly diagnosed hypertensives with syndrome X using recently published criteria. All patients received 4 mg of perindopril and were followed for 12 weeks. Perindopril improved all studied biochemical parameters except homocysteine in the non-syndrome X group. There was a statistically significant decrease in cardiac risk in both groups taking perindopril. However, the syndrome X hypertensives exhibited substantial improvement in markers of insulin resistance and inflammation. The biochemically observable metabolic defects in syndrome X are amenable to perindopril therapy in this study.